Ricerc@Sapienza

The Test Blanket Module (TBM) experimental campaign in the International Tokamak Experimental Reactor (ITER) is expected to be a fundamental opportunity to characterize the wide range of phenomena expected to occur in a full-sized blanket. This component is of fundamental importance for a future Fusion Power Plant (FPP) since it will ensures the reactor fuel supply, power extraction, and radiation shielding. The EU is currently pursuing two different TBM mock-ups to be tested in ITER revolving around different breeder and coolant concepts. The objective of this research proposal deals with the Water-Cooled Lithium Lead (WCLL) mock-up that it is envisioned to employ water in PWR-like conditions as coolant and lithium lead eutectic alloy (PbLi) as tritium breeder and carrier. Since PbLi is electrically conductive, flow within the TBM is expected to interact with the tokamak magnetic field and to transition to a magnetohydrodynamic (MHD) regime. This phenomenon carries many subtle consequences for the blanket (and TBM) design, one of the most important being the enhanced pressure loss due to electromagnetic drag. This research proposal aims to perform a set of in-depth MHD analyses aimed to characterize the most relevant phenomena in the TBM breeding zone (BZ): 2D flow in rectangular duct with non-uniform conductivity, coupled counter-flow channels connected by a hairpin bend, 3D flow around complex geometry obstacles, and BZ/manifold entrance effect. The work proposed starts from the significant know-how accumulated by the DIAEE research group in the last years for the simulation of MHD flows in the WCLL blanket and it is structured in a progressive way from simplified to higher complexity numerical models. Obtained results will directly impact the R&D activities on TBM design, mostly by developing scaling laws for several magneto-hydraulic elements, that will make possible to optimize and streamline the PbLi flow path about pressure loss minimization.